As shown in FIG. 5, a pipe joint A of the prior art is composed of a connection portion B and two coupling handles C. The connection portion B is provided in the interior thereof with a center through hole D and in the periphery thereof with two pivoting seats E opposite in location to each other. The pivoting seats E are provided respectively with a pivoting hole F and are fastened pivotally with the coupling handles C. The coupling handles C are fastened pivotally with the pivoting seats E such that the retaining portions G of the coupling handles C are slightly extended into the center through hole D so as to facilitate the coupling of the pipes by means of the coupling handles C.
Such a prior art joint as described above is defective in design in that the coupling handles of the pipe joint are prone to be caught accidentally by a moving object to cause the loosening of the connection portion. Such an incident can turn out to be a serious or even deadly mishap if the pipe line is used to convey the gas, the toxic chemicals, etc.